Officials Seek to Alter System That Pits the Eastern Part of the State Against the West

DENVER—Officials in Colorado want to change how water is divvied up among its swelling population by altering a system that relies on piping water from west of the Rocky Mountains to thirsty cities in the east.

The state’s first water plan, a draft of which was approved Wednesday by the Colorado Water Conservation Board, acknowledges that current usage patterns are unsustainable. The plan seeks to ease rifts between Colorado’s water-rich, less populated Western Slope and the dryer, faster-growing Front Range by calling for...